Rock drill



July 20, 1926. 1,593,472

I L: REVOR ROCK DRILL Filed July 10, 1922 Patented July 20, 1925,

n aii s ra'rss 1,593,42-2 ea rear orries L'EonE'von, or LYONaronivreriv; NEW YORK.

nook DRILL.

Application filed July 10, 1922.

nism should the drill steel break during the lodrillin'g operation. Thebreaking of drill steelis a common occurrence, and ofttimes results in'in'jury'tothe'drill runner since "the drill will be projected upwardlyunder the action of the feed baras soon as the "drill steel breaks,which causes the drill runner to "lose his footing and control of thedrill, and ifworking on a ledge or in a dangerous location the drillrunner will be injured, and "often fatally. My invention is thereforedirected to means for overcoming these objections and dangers by theinstallation of an automatically operated cut-oil. whereby themainairsupply will be cut-oil at the instant the drill steel breaks, therebypreventing the feeding mechanism from exerting-an upward movement to thedrill. lVith these and other objects inview, this invention resides inthe novel features of construction,formation, combination andarrangement of parts to be hereinafter more fully described, claimed andillustrated in the drawing, in which Figure 1 is a. fragmentary sideelevation of a drill equipped with the device.

Figure 2 is a fragmentary sectional View through the front head.

Figure 3 is a longitudinal sectional view through the valve.

Referring to the drawing, 1 designates the cylinder, and 2 the fronthead in which is clamped the chuck 3, said chuck having a longitudinalgroove 4: formed therein, the purpose of which will appear later. Thefront head 2 is provided with a. chamber 5 in which is located forreciprocating move ment the tappet- 6 actuated by blows from the hammer7, said hammer being located in the cylinder, as is usual.

Live air is supplied to the cylinder in the usual manner to operate thehammer 7, the flow thereof being controlled by the throttle valve 8which also controls the passage of air to the feed barrel 9 to extendthe feed bar 10 therefrom, as is customary in drills of this type. i

The construction thus far described, with Serial No. 573,875.

the exception of the groove 4 is well known. The usual throttle valve 8is rotatably mounted on the head 11 which has its major end providedwith a chamber 12, the valve 8 being equipped with an annular seat 13,the purpose of which will later appear. Threaded in the head 11, andalined with the valve 8 is a bushing 14, and threaded in said bushingis'the branch 15 of the spud 16, said'spud having connected thereto, inthe customary manner the air supply hose 1'7. A stutling box 18 iscarried by the spud 16, and slidable therein is the stem 19 of,

the circular head 20, said stem bridging the chamber 21 of the spud '16,and extending axially through the branch 15 thereof. The head QO'hasformed integral therewith a valve disk 22, which is separated from thehead by an annular groove 23, thereby producing an annular shoulder 2d,the purpose of which will appear later.

Encircling the stem 19 is acoil spring 25, one terminal of which bearsagainst the head 20, while the other terminal engages the adjacent: endof the stufiing box 18, said spring serving to urge the valve disktowards the seat 13. However, under normal conditions,

it ise'ssential that the valve 22 be held unscated that air may flowfreely from the throttle valve to the hammer chamber and feed barbarrel. In order to hold the valve disk 22 unseated, a rod 26 isemployed, said rod being slidably engaged in the stufiing box 27 carriedby the throttle valve casing 28. The lower end of the rod extends intothe casing s8 and is adapted to engage the shoulder 24, thereby holdingthe valve disk unseated, and the spring contracted.

The upper end of the rod 26 terminates in a hook 29, the shank 30thereof being bent downwardly and parallel to the adjacent portion ofthe rod, said shank being adapted to lie in the groove 4 formed in thechuck 3, and consequently interiorly of the front head 2. It will beobvious that the lower end of the shank 30 is normally spaced a slightdistance vertically from the tappet 6, whereby the tappet may normallyrecipro cate without contacting with said shank. It will be of courseunderstood that as long as the drill steel is intact, the movement ofthe tappet will be limited owing to the fact that the bit of the drillsteel will engage the bottom of the drill bore, and consequently thetappet will be prevented from moving upwardly a sufficient distance tocause the lower end of the shank 30 to be engaged by the tappet.However, when the drill steel breaks and resistance thereto is relieved,the tappet will instantly move upwardly a distance to cause it to engagethe shank 30, whereupon the rod 26 will slide upwardly until its lowerend disengages the shoulder 24, whereupon the valve disk 22, under theaction of the spring 25 will be instantly forced inwardly until thevalve seats on the seat 13, thereby cutting off the supply of airsimultaneously to the feed bar barrel and hammer chamber. Thus it willbe seen that the instant the drill steel breaks that the supply of airto the pneumatically operated feeding mechanism will be cut off, therebypreventing the drill from being projected sharply upwardly, as nowfrequently occurs, with the result that the drill runner is seriously,and possibly fatally injured due to losing his footing in an attempt tocontrol the drill as it moves upwardly under the action of the feedingmechanism.

The head 20 is provided with a plurality of perforations or ports 31,through which live air is permitted to pass long as the valve disk 22 isunseated, and consequently under normal conditions the hammer andfeeding mechanism will receive the neces sary live air.

A pin 32 may be provided to engage a perforation formed in the stem 19,whereby the valve disk 22 may be positively held unsealed, in an obviousmanner.

ll'hat is claimed is 1. In a fluid operated drill, a cylinder, a chuckassociated with the cylinder and having a groove formed therein, ahammer movable in the cylinder, :1 tappet actuated by the hammer forstriking a drill steel, a pneumatically operated feeding mechanismassociated with the cylinder, a throttle valve associated with thecylinder for controlling the passage of air to the eylinder and feedingmechanism, a spring pressed valve disk, a shoulder associated with thevalve disk. a rod having its lower end engaged with the shoulder to holdthe valve dis in its inoperative. position, a hook carried by the upperend of the rod and having its shank engaged in said groove to engage thetappet when the same moves upwardly, thereby shifting the rod to releasethe valve disk to permit the same to cut otl the supply of air throughthe throttle valve, as and for the purpose set forth.

2. In a fluid operated drill, a cylinder. a hammer movable therein. atappet operable by the hammer for striking a drill steel, apneumatically operated feeding mechanism associated with the cylinder. athrottle valve for the cylinder for controlling the passage of fluid tothe cylinder and feeding mechanism, a valve disk associated with thethrottle valve adaoted to seat thereon at times. means for normallyholding the valve disk unseated, said means being operable by the tappetupon abnormal movement thereof to permit said valve disk to seat and cutoil' the supply of fluid to the throttle valve. a nd thus to the feedingmechanism, as and for the purpose set forth.

In testimony whereof I have hereunto set my hand.

LEO REYO R.

